fix: vault paths, TOTP caching, and keyboard nav on filtered list

- Fix .idfoto/ prefix for salt and params.json in vault.ts
- Cache TOTP secrets by entry ID to avoid re-fetching every second
- Fix keyboard navigation to use filtered entries, not unfiltered
- Add window.close() on Escape from entry list

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

extension/src/service-worker/vault.ts

@@ -28,8 +28,8 @@ export interface VaultMeta {
 
 /// Read the vault salt and KDF params from the git repo.
 export async function fetchVaultMeta(git: GitHost): Promise<VaultMeta> {
-  const saltBytes = await git.readFile('salt');
-  const paramsRaw = await git.readFile('params.json');
+  const saltBytes = await git.readFile('.idfoto/salt');
+  const paramsRaw = await git.readFile('.idfoto/params.json');
   const paramsJson = new TextDecoder().decode(paramsRaw);
   return { salt: saltBytes, paramsJson };
 }